hrpF of Xanthomonas campestris pv. vesicatoria Encodes an 87-kDa Protein with Homology to NolX of Rhizobium fredii

The gram-negative bacterium Xanthomonas campestris pv. vesicatoria is the causal agent of bacterial spot disease on pepper and tomato plants. The main hrp (hypersensitive reaction and pathogenicity) gene cluster in X. campestris pv. vesicatoria spans a 23-kb chromosomal region, comprising six complementation groups designated hrpA to hrpF. Analysis of the hrpF locus revealed a single open reading frame encoding HrpF (86.4 kDa). HrpF is predominantly hydrophilic, and contains two hydrophobic domains in the C terminus. An interesting feature is the presence of two imperfect direct repeats in the N-terminal region. Deletion studies showed that one repeat is sufficient for function. Epitope tagging of HrpF allowed detection of the protein in X. campestris pv. vesicatoria. Subcellular localization studies suggest that HrpF is both in the soluble fraction and in the inner membrane. Interestingly, HrpF is 48% identical (67% similar) to the Rhizobium fredii NolX protein that is part of the host specificity locus. Since several Hrp proteins are believed to be components of the type III Hrp protein secretion apparatus, allowing export of proteins essential for the interaction with the plant, the possible role of hrpF and nolX in secretion is discussed.

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Identification of Genes in Xanthomonas campestris pv. vesicatoria Induced during Its Interaction with Tomato

Journal of Bacteriology ◽

10.1128/jb.00320-07 ◽

2007 ◽

Vol 189 (17) ◽

pp. 6359-6371 ◽

Cited By ~ 38

Author(s):

Dafna Tamir-Ariel ◽

Naama Navon ◽

Saul Burdman

Keyword(s):

Xanthomonas Campestris ◽

Disease Process ◽

In Planta ◽

Gene Encoding ◽

Host Interaction ◽

Citrate Transporter ◽

Knockout Mutants ◽

Bacterial Spot Disease

ABSTRACT Xanthomonas campestris pv. vesicatoria is the causal agent of bacterial spot disease of tomato and pepper. The disease process is interactive and very intricate and involves a plethora of genes in the pathogen and in the host. In the pathogen, different genes are activated in response to the changing environment to enable it to survive, adapt, evade host defenses, propagate, and damage the host. To understand the disease process, it is imperative to broaden our understanding of the gene machinery that participates in it, and the most reliable way is to identify these genes in vivo. Here, we have adapted a recombinase-based in vivo expression technology (RIVET) to study the genes activated in X. campestris pv. vesicatoria during its interaction with one of its hosts, tomato. This is the first study that demonstrates the feasibility of this approach for identifying in vivo induced genes in a plant pathogen. RIVET revealed 61 unique X. campestris pv. vesicatoria genes or operons that delineate a picture of the different processes involved in the pathogen-host interaction. To further explore the role of some of these genes, we generated knockout mutants for 13 genes and characterized their ability to grow in planta and to cause disease symptoms. This analysis revealed several genes that may be important for the interaction of the pathogen with its host, including a citH homologue gene, encoding a citrate transporter, which was shown to be required for wild-type levels of virulence.

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Streptococcus mutans Murein Hydrolase

Journal of Bacteriology ◽

10.1128/jb.187.22.7863-7865.2005 ◽

2005 ◽

Vol 187 (22) ◽

pp. 7863-7865 ◽

Cited By ~ 13

Author(s):

Diana M. Catt ◽

Richard L. Gregory

Keyword(s):

Amino Acid ◽

Streptococcus Mutans ◽

Signal Sequence ◽

Surface Protein ◽

Open Reading Frame ◽

Direct Repeats ◽

Reading Frame ◽

Allelic Replacement ◽

C Terminus ◽

Murein Hydrolase

ABSTRACT Allelic replacement of the C terminus of a Streptococcus mutans surface protein affects murein hydrolase activity. The targeted open reading frame encodes a 67-kDa protein (SmaA) with an N-terminal signal sequence and cleavage site, three 46-amino-acid (aa) direct repeats, and two 88-aa direct repeats. The identical autolytic profile was obtained using a sortase mutant (SrtA−).

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Sterol 14α-demethylase activity in Streptomyces coelicolor A3(2) is associated with an unusual member of the CYP51 gene family

Biochemical Journal ◽

10.1042/bj20011380 ◽

2002 ◽

Vol 364 (2) ◽

pp. 555-562 ◽

Cited By ~ 21

Author(s):

David C. LAMB ◽

Kay FOWLER ◽

Tobias KIESER ◽

Nigel MANNING ◽

Larissa M. PODUST ◽

...

Keyword(s):

Streptomyces Coelicolor ◽

Open Reading Frame ◽

Reading Frame ◽

E Coli ◽

Transposon Insertion ◽

Cell Extracts ◽

C Terminus ◽

Demethylase Activity ◽

First Time

The annotation of the genome sequence of Streptomyces coelicolor A3(2) revealed a cytochrome P450 (CYP) resembling various sterol 14α-demethylases (CYP51). The putative CYP open reading frame (SC7E4.20) was cloned with a tetrahistidine tag appended to the C-terminus and expressed in Escherichia coli. Protein purified to electrophoretic homogeneity was observed to bind the 14-methylated sterols lanosterol and 24-methylene-24,25-dihydrolanosterol (24-MDL). Reconstitution experiments with E. coli reductase partners confirmed activity in 14α-demethylation for 24-MDL, but not lanosterol. An S. coelicolor A3(2) mutant containing a transposon insertion in the CYP51 gene, which will abolish synthesis of the functional haemoprotein, was isolated as a viable strain, the first time a CYP51 has been identified as non-essential. The role of this CYP in bacteria is intriguing. No sterol product was detected in non-saponifiable cell extracts of the parent S. coelicolor A3(2) strain or of the mutant. S. coelicolor A3(2) CYP51 contains very few of the conserved CYP51 residues and, even though it can catalyse 14α-demethylation, it probably has another function in Streptomyces. We propose that it is a member of a new CYP51 subfamily.

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Factor Xa Enhances the Binding of Tissue Factor Pathway Inhibitor to Acidic Phospholipids

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650369 ◽

1996 ◽

Vol 75 (05) ◽

pp. 796-800 ◽

Cited By ~ 10

Author(s):

Sanne Valentin ◽

Inger Schousboe

Keyword(s):

Tissue Factor ◽

Tissue Factor Pathway Inhibitor ◽

Factor Xa ◽

Microtitre Plate ◽

C Terminus ◽

Microtitre Plate Assay ◽

Kunitz Domain ◽

Tissue Factor Pathway ◽

Acidic Phospholipids

SummaryIn the present study, the interaction between tissue factor pathway inhibitor (TFPI) and phospholipids has been characterized using a microtitre plate assay. TFPI was shown to bind calcium-independently to an acidic phospholipid surface composed of phosphatidylserine, but not a surface composed of the neutral phosphatidylcholine. The interaction was demonstrated to be dependent on the presence of the TFPI C-terminus. The presence of heparin (1 U/ml, unfractionated) was able to significantly reduce the binding of TFPI to phospholipid. The interaction of TFPI with phosphatidylserine was significantly decreased in the presence of calcium, but this was counteracted, and even enhanced, following complex formation of TFPI with factor Xa prior to incubation with the phospholipid surface. Moreover, a TFPI variant, not containing the third Kunitz domain and the C-terminus, was unable to bind to phospholipid. However, following the formation of a TFPI/factor Xa-complex this TFPI variant was capable of interacting with the phospholipid surface. This indicates that the role of factor Xa as a TFPI cofactor, at least in part, is to mediate the binding of TFPI to the phospholipid surface.

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Does a Ribosome Really Read? On the Cognitive Roots and Heuristic Value of Linguistic Metaphors in Molecular Genetics. Part 2

Russian Journal of Philosophical Sciences ◽

10.30727/0235-1188-2020-63-2-46-62 ◽

2020 ◽

Vol 63 (2) ◽

pp. 46-62

Author(s):

Suren T. Zolyan

Keyword(s):

Information Processing ◽

Genetic Information ◽

Formal Organization ◽

Dual Nature ◽

Reading Frame ◽

The Core ◽

Genetic Information Processing ◽

Cognitive Frame ◽

Effective Instrument

We discuss the role of linguistic metaphors as a cognitive frame for the understanding of genetic information processing. The essential similarity between language and genetic information processing has been recognized since the very beginning, and many prominent scholars have noted the possibility of considering genes and genomes as texts or languages. Most of the core terms in molecular biology are based on linguistic metaphors. The processing of genetic information is understood as some operations on text – writing, reading and editing and their specification (encoding/decoding, proofreading, transcription, translation, reading frame). The concept of gene reading can be traced from the archaic idea of the equation of Life and Nature with the Book. Thus, the genetics itself can be metaphorically represented as some operations on text (deciphering, understanding, code-breaking, transcribing, editing, etc.), which are performed by scientists. At the same time linguistic metaphors portrayed gene entities also as having the ability of reading. In the case of such “bio-reading” some essential features similar to the processes of human reading can be revealed: this is an ability to identify the biochemical sequences based on their function in an abstract system and distinguish between type and its contextual tokens of the same type. Metaphors seem to be an effective instrument for representation, as they make possible a two-dimensional description: biochemical by its experimental empirical results and textual based on the cognitive models of comprehension. In addition to their heuristic value, linguistic metaphors are based on the essential characteristics of genetic information derived from its dual nature: biochemical by its substance, textual (or quasi-textual) by its formal organization. It can be concluded that linguistic metaphors denoting biochemical objects and processes seem to be a method of description and explanation of these heterogeneous properties.

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A CACNA1A variant associated with trigeminal neuralgia alters the gating of Cav2.1 channels

Molecular Brain ◽

10.1186/s13041-020-00725-y ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Eder Gambeta ◽

Maria A. Gandini ◽

Ivana A. Souza ◽

Laurent Ferron ◽

Gerald W. Zamponi

Keyword(s):

Trigeminal Neuralgia ◽

Missense Mutation ◽

Neurotransmitter Release ◽

Trigeminal System ◽

Wild Type ◽

Calcium Dependent ◽

Whole Cell Patch Clamp ◽

C Terminus ◽

Dependent Inactivation

AbstractA novel missense mutation in the CACNA1A gene that encodes the pore forming α1 subunit of the CaV2.1 voltage-gated calcium channel was identified in a patient with trigeminal neuralgia. This mutation leads to a substitution of proline 2455 by histidine (P2455H) in the distal C-terminus region of the channel. Due to the well characterized role of this channel in neurotransmitter release, our aim was to characterize the biophysical properties of the P2455H variant in heterologously expressed CaV2.1 channels. Whole-cell patch clamp recordings of wild type and mutant CaV2.1 channels expressed in tsA-201 cells reveal that the mutation mediates a depolarizing shift in the voltage-dependence of activation and inactivation. Moreover, the P2455H mutant strongly reduced calcium-dependent inactivation of the channel that is consistent with an overall gain of function. Hence, the P2455H CaV2.1 missense mutation alters the gating properties of the channel, suggesting that associated changes in CaV2.1-dependent synaptic communication in the trigeminal system may contribute to the development of trigeminal neuralgia.

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Genetic Analysis of the Drosophila 63F Early Puff: Characterization of Mutations in E63-1 and maggie, a Putative Tom22

Genetics ◽

10.1093/genetics/156.1.229 ◽

2000 ◽

Vol 156 (1) ◽

pp. 229-244

Author(s):

Martina Vaskova ◽

A M Bentley ◽

Samantha Marshall ◽

Pamela Reid ◽

Carl S Thummel ◽

...

Keyword(s):

Salivary Gland ◽

Genetic Analysis ◽

Polytene Chromosomes ◽

Reading Frame ◽

Protein Levels ◽

Ef Hand ◽

Larval Salivary Gland ◽

Complementation Groups ◽

Inducible Genes ◽

Early Puff

Abstract The 63F early puff in the larval salivary gland polytene chromosomes contains the divergently transcribed E63-1 and E63-2 ecdysone-inducible genes. E63-1 encodes a member of the EF-hand family of Ca2+-binding proteins, while E63-2 has no apparent open reading frame. To understand the functions of the E63 genes, we have determined the temporal and spatial patterns of E63-1 protein expression, as well as undertaken a genetic analysis of the 63F puff. We show that E63-1 is expressed in many embryonic and larval tissues, but the third-instar larval salivary gland is the only tissue where increases in protein levels correlate with increases in ecdysone titer. Furthermore, the subcellular distribution of E63-1 protein changes dynamically in the salivary glands at the onset of metamorphosis. E63-1 and E63-2 null mutations, however, have no effect on development or fertility. We have characterized 40 kb of the 63F region, defined as the interval between Ubi-p and E63-2, and have identified three lethal complementation groups that correspond to the dSc-2, ida, and mge genes. We show that mge mutations lead to first-instar larval lethality and that Mge protein is similar to the Tom22 mitochondrial import proteins of fungi, suggesting that it has a role in mitochondrial function.

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The critical role of cytochrome c maturation (CCM) system in the tolerance of Xanthomonas campestris pv. campestris to phenazines

Pesticide Biochemistry and Physiology ◽

10.1016/j.pestbp.2019.02.003 ◽

2019 ◽

Vol 156 ◽

pp. 63-71 ◽

Cited By ~ 2

Author(s):

Jian Wu ◽

Xiayan Pan ◽

Shu Xu ◽

Yabing Duan ◽

Jianying Luo ◽

...

Keyword(s):

Cytochrome C ◽

Xanthomonas Campestris ◽

Critical Role ◽

Cytochrome C Maturation ◽

Xanthomonas Campestris Pv Campestris

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Characterization of Xanthomonas axonopodis pv. phaseoli isolates

Summa Phytopathologica ◽

10.1590/s0100-54052008000300004 ◽

2008 ◽

Vol 34 (3) ◽

pp. 228-231 ◽

Cited By ~ 2

Author(s):

Willian Mário de Carvalho Nunes ◽

Maria Júlia Corazza ◽

Silvana Aparecida Crestes Dias de Souza ◽

Siu Mui Tsai ◽

Eiko Eurya Kuramae

Keyword(s):

Xanthomonas Campestris ◽

Random Amplified Polymorphic Dna ◽

Hypersensitive Reaction ◽

Chain Reaction ◽

Xanthomonas Axonopodis ◽

Paulo State ◽

Total Dna ◽

Polymerase Chain ◽

Bacterial Plant Pathogen

A simple, quick and easy protocol was standardized for extraction of total DNA of the bacteria Xanthomonas axonopodis pv. phaseoli. The DNA obtained by this method had high quality and the quantity was enough for the Random Amplified Polymorphic DNA (RAPD) reactions with random primers, and Polymerase Chain Reaction (PCR) with primers of the hypersensitivity and pathogenicity gene (hrp). The DNA obtained was free of contamination by proteins or carbohydrates. The ratio 260nm/380nm of the DNA extracted ranged from 1.7 to 1.8. The hrp gene cluster is required by bacterial plant pathogen to produce symptoms on susceptible hosts and hypersensitive reaction on resistant hosts. This gene has been found in different bacteria as well as in Xanthomonas campestris pv. vesicatoria (9). The primers RST21 and RST22 (9) were used to amplify the hrp gene of nine different isolates of Xanthomonas axonopodis pv. phaseoli from Botucatu, São Paulo State, Brazil, and one isolate, "Davis". PCR amplified products were obtained in all isolates pathogenic to beans.

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